PCB populated

PCB

Group of boards

Overview

The water controller project was commissioned by an American client, who ultimately had 50,000 units manufactured. The device was designed to control a valve while consuming minimal power.

The board incorporated an ATTiny MCU and was powered by a 9V battery with custom connectors. To alert users when the battery was running low, the board also included voltage monitoring functionality.

The project went through three iterations, with the final version being the most cost-effective. This version replaced the original MCU with a 9-cent MCU, saving almost $1 per unit.

Firmware

There were two versions of the firmware. The first version was designed for the ATTiny. Its main function was to control the valve and monitor the inputs. At the end of each cycle, it would power it self off.

The second version was just ported to the 9-cent MCU, which worked in the same way.